Costco has not been having the best week, between the live scorpion found on a bunch of bananas in a store in Nova Scotia and the $19 million judgement against them for ripping off Tiffany & Co. rings. Unfortunately, their golf ball lawsuit is also catching up with them.

Costco's Kirkland Signature golf balls became one of their most wildly popular products, frequently sold out or when they were in stock, in short supply. Under their Kirkland Signature brand, Costco promises its products "must be equal to or better than the national brands."

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That cult popularity at that price point ($15 per dozen) rubbed Acushnet, the makers of Titleist golf balls, the wrong way. They sent Costco a letter alleging false advertising because of the Kirkland Signature promise, and Costco retaliated by asking for a declaratory judgement that the warehouse club's ball was not infringing on Acushnet's golf ball patents.

Now, almost five months later, Acushnet is ready to tee-off. They predictably responded with a blanket denial of all Costco's claims, but they've also volleyed back with a 284-page countersuit.

About 243 pages are in-the-weeds, golf-ball science. But they also break down the 10 alleged infringements on Acushnet-owned patents, while alleging that the Kirkland Signature guarantee amounts to false advertising.

On each of their infringement claims, they argue that they "have been, are, and will continue to be seriously damaged and irreparably harmed" unless the court finds Costco guilty of infringement.

Acushnet's filing does not ask for a specific dollar amount, instead calling for a jury trial over the alleged infringing patents. They also ask that the court help Acushnet "recover Costco's illicit profits and damages arising out of the acts of deception described above, and a sum equal to three times such profits and damages" be awarded to the golf ball manufacturer.

Back when Costco brought their suit in March, many worried that Acushnet's prowess in this field – holding more than U.S. patents in golf ball technology than any other manufacturer (at least 1,200), and a history of defending that portfolio through years of litigation – made the Korean company a more formidable foe than Costco was expecting. Coupled with the difficulty of invalidating patents, and it's could be a long fight.

According to the court documents, the two parties are scheduled to hold a conference about the initial lawsuit by August 17, and will provide a U.S. District judge with a joint status report by August 31.

In the meantime, the Kirkland Signature balls have been sold out since spring.